基于匹配列比较两个SQL表

Question

I have two tables, T1 and T2. T1 looks like this:

    ID      Type      Date
    _____________________________
    1       CA        11-17-2018
    2       BA        7-12-2018
    3       CA        4-1-2018
    4       BA        1-17-2018
    5       CA        9-30-2018

And T2 looks like this:

    ID      Type      Date
    _____________________________
    1       CA        11-17-2018
    2       BA        3-1-2018
    3       CA        4-1-2018
    4       CA        1-17-2018
    5       CA        10-3-2018

I need a way to compare rows from the two tables that have matching IDs and see if the other values match or if they're different. I only want the output table to contain those IDs with differing values, and display those values. Thanks in advance.

Answer 1

Try this:

SELECT T1.ID, T1.Type as T1Type, T2.Type as T2Type, T1.Date as T1Date, T2.Date as T2Date
FROM T1
INNER JOIN T2
ON T1.ID = T2.ID
WHERE T1.DATE <> T2.DATE
OR T1.Type <> T2.Type

Notice that this query will only return result where the ID is present in both tables.

Answer 2

I think you need below something, inner join and comparison

  select T1.*,T2.* from T1 inner join T2 on T1.id=T2.id
    where T1.Type!=T2.Type   and T1.Date!=T2.Date

Answer 3

You would use join :

select t1.*, t2.*
from t1 join
     t2
     on t1.id = t2.id
where (t1.type <> t2.type) or (t1.date <> t2.date)

Answer 4

you can put one foreign key in one of this tables, who will make reference to the other.

When you make a select, you can do a join of one table with other by the primary key and the foreign key.

SELECT column FROM table1 JOIN table2 ON table1.id_pk = table2.id_fk WHERE condition;

in WHERE you put something like

WHERE (table1.id != table2.id) OR (table1.type != table2.type) OR (table1.date != table2.date);